$\dfrac{3}{12} + \dfrac{1}{2} = {?}$
${\dfrac{3}{12}}$ ${\dfrac{1}{2}}$ $+$ ${\dfrac{3 \times 1}{12 \times 1}}$ ${\dfrac{1 \times 6}{2 \times 6}}$ $+$ ${\dfrac{3}{12}}$ ${\dfrac{6}{12}}$ $+$ $ = \dfrac{{3} + {6}}{12} $ $ = \dfrac{9}{12}$